My gelding was being a stinker with holding his feet for me. I could normally pick up his foot (although sometimes he would brace his leg and wouldn't let me pick it up). We had his old owner come out to help us, and we worked on picking up his feet for about 45 minutes. His old owner said that he had never been great with picking up his feet, and someone had told her to just hold his foot until he stops struggling.
Now, I understand it can be hard to hold on when you have a 1,000 pound animal trying to wrench his foot out of your hands, but it is possible! His previous owner lifted up his feet first, and it was scary to watch...She's probably only 105 pounds (and I'm like 115, two small girls). She held on until he stopped struggling, waited a few seconds, and then let go of his foot. She did that with all of his feet, then I took a try. He yanked a lot with me, but eventually we got to the point where he didn't struggle at all for the remainder of our time. Haha, then the farrier came out while we were working (he was a hour early) and said he could do his feet right then. Boy, Lookit was a complete angel!
I practice lifting up his feet every time I go out, and he keeps getting better :) Occasionally he will strike out with a front foot, but then I just take more time with his feet. I was even able to just go out into the pasture and lift up all of his feet very easily. If he had wanted to, he could have just ran away as he didn't have a halter or anything on.
So, just be patient and consistent. You'll have bad days (we all do!), but just try to fight through them!
Also, make sure you're careful, as I was left with some nice bruises after our first time working on it (hooves are hard!). My arms were really sore too...I had a fun time at work that day =P Remember, however much your horse likes you, he can accidentally injure you. The reason I say this is because I've heard someone say that they were scared of doing the feet thing at first, but then they thought, "Aw, he can't kill me." Psh! Yes he can! =P
Well, I hope you can get it figured out!